Yellow wool-dye and process of making same.



UNITED STATES PATENT OFFICE.

JULIUS HERBABN Y, OF OFFENBAOH-ON-THE-MAIN, GERMANY, ASSIGNOR TO K. OEHLER, ANILIN AND ANILIN FARBEN-FABRIK, OF SAME PLACE.

YELLOW WOOL-DYE AND PROCESS' OF MAKING SAME.

SPECIFICATION forming part Of LfitrS Patent NO. 627,690, dated June 2'7, 1899. Application filed February 20, 1899. Serial No. 706,125. Specimen's.)

To all whom it may concern.-

Be it known that I, JULIUS HERBABNY, doctor of philosophy, residing at Offenbach-onthe-Main, in the Grand Duchy of Hessen, Empire of Germany, have invented new and useful Improvements in the Manufacture of a New Yellow D yestuff for W001, (for which the firm of K. Oehler has applied for Letters Patent in Germany, 0. 3,07 5/22 of January 25,

1899,) of which the following is aspecification.

By the action first of one molecule of para nitrophenylhydrazin upon oXalo-acetic ether and then of one molecule of diazo-sulfanilic acid upon the thus-obtained pyrazolone a newvaluable dyestufi results which dyes'woolen goods in very fast yellow tints.

I proceed as follows, parts being by weight: Nine and four-tenths (9.4) parts of oxal'oacetic ether, seven (7) parts of sodium acetate, and nine and one-half (9.5) parts of the hydrochlorate of nitro-phenyl-hydrazin are thoroughly stirred in about one hundred (100) parts of water. Slowly raise the temperature and maintain it at about forty-five to fifty degrees centigrade, (45 to C.) The formation of the condensation product takes place instantaneously. After cooling add twentyone (21) parts of caustic-soda lye of 35Baum. Then stir during three hours at ordinary temperature and about one hour'at ninety to one hundred (90 to lOO 0.) degrees centigrade.

The carboxylic acid of nitro-phenyl-pyrazm lone thus formed is precipitated by adding eight (8) parts of concentrated sulfuric acid of 66 Baum diluted with water to a twentyper-cent. acid and then filtered off.

In order to form the dyestuff, redissolve the obtained nitro-phenyl-pyrazolone-carboxylicv acid in five hundred (500}:parts of water containing eighteen and one-half (18.5) parts of sodium carbonate. To the same effect the above-named alkaline solution of the condensation product may alsol be used. Then at zero degree add the quantity of diazo-sulfanilic acid which results from dissolving 9.7 parts of the sodium'salt of sulfanilic acid in one hundred parts of water, subsequently adding 3. 6 parts of sodium nitrite and pouring the whole into twenty parts of hydrochloric acidof 20 Baum diluted with one hundred parts of water. Then stir during twelve (12)hours, heat the mass, precipitate with common salt, filter, press, and dry.

The dyestuff thus obtained forms a light orange-yellow powder easily soluble in water, with a yellow to orange color, which on addition of mineral acids turns slightly to yellow and yellowish green, while caustic-soda lye turns it a little darker.

The new dyestuff compares very favorably with tartrazin. On wool it gives more level shades, is fast to milling, and will stand the action of limemuch better.

- Now what I claim, and desire to secure by Letters Patent, is the following:

1. The process of making ayellow dyestuff for dyeing wool, consisting in the formation, first of para-nitro-phenyl-pyrazolone-carboxylic acid, by the action of one molecule of para-nitro-phenyl-hydrazin upon one molecule of oxalo-acetic ether, then combining it with one molecule of diazo-sulfanilic acid.

2. As a new article of manufacture, the yellow dyestufi. which derives from para-nitrophenyl-pyrazolone-carboxylic acid and diazosulfanilic acid, and which is characterized by the following properties, it forms a light orange powder, easily soluble in water, slightly soluble in alcohol of ninety per cent. with a yellow color; the aqueous solution, on addition of caustic-soda lye, turns a little darker and becomes rather lighter when adding mineral acids; it dissolves in concentrated sulf uric acid with a yellowish-brown color, which solution on diluting with a little water separates out a yellow flocculent precipitate,which on adding more Water redissolves with a yellow color and dyes woolen goods in greenishyello'w tints, which are very fast to milling. 

